New Customer Reporting in Meta

1. Why Reporting Changes After Switching to NewCustomerPurchase

Once your campaigns are optimized for the NewCustomerPurchase event, the campaign objective changes. Instead of maximizing the total number of purchases, Meta is now optimizing to acquire as many new customers as possible.

As a result, the way campaign performance should be evaluated changes as well.

Before the switch, performance was typically measured using purchase-related metrics such as the total number of purchases or Cost per Purchase. After switching to NewCustomerPurchase, your primary focus should shift to new customer acquisition KPIs.

Example

Although Campaign B generated fewer purchases overall, it acquired significantly more new customers with the same budget while achieving a lower Customer Acquisition Cost (CAC).

If your objective is new customer acquisition, Campaign B is therefore the stronger performer.

After switching to NewCustomerPurchase, campaign performance should primarily be evaluated based on new customer KPIs, rather than traditional purchase metrics alone.

1.1 Why Some Standard KPIs Change

After switching optimization goals, the meaning of certain standard metrics in Meta Ads Manager also changes.

Most notably, the Results and Cost per Result columns always reflect the campaign's current optimization goal.

Example

Before the switch

• Optimization Goal: Purchase

• Amount Spent: €5,000

Attributed conversions:

• 100 Purchases

• 50 NewCustomerPurchases

Cost per Result: €50 (€5,000 ÷ 100 Purchases)

After the switch

• Optimization Goal: NewCustomerPurchase

• Amount Spent: €5,000

Attributed conversions:

• 100 Purchases

• 50 NewCustomerPurchases

Cost per Result: €100 (€5,000 ÷ 50 NewCustomerPurchases)

In this example, the campaign performance is identical.

The only difference is that Cost per Result now represents Customer Acquisition Cost (CAC) instead of Cost per Purchase.

⚠ Important:
Unlike Google Ads, this change in Meta affects only a small number of standard metrics—primarily Results and Cost per Result.

Other metrics such as Purchases, Purchase ROAS, and Purchase Conversion Value remain unchanged and are clearly labeled in Ads Manager. Meta explicitly indicates which event each metric refers to (for example, Purchase or NewCustomerPurchase), making misinterpretation much less likely than in Google Ads.

2. Key KPIs After Switching to NewCustomerPurchase

After switching to NewCustomerPurchase, campaign performance should no longer be evaluated solely using Meta's traditional purchase metrics.

Instead, the most important KPIs are:

• NewCustomerPurchases (Number of New Customers)

• NewCustomerPurchase Value (New Customer Revenue)

• Customer Acquisition Cost (CAC) (Cost per NewCustomerPurchase)

• NC ROAS (Custom Column)

• New Customer Share (NC%) (Custom Column)

These metrics help you understand:

• How many new customers your campaigns acquired

• What percentage of total customers were new customers

• How profitable your new customer acquisition efforts actually are

For this reason, campaign performance should primarily be evaluated from a new customer acquisition perspective rather than focusing exclusively on overall purchase metrics.

3. Using Custom Events and Custom Conversions Correctly in Reporting

For every new customer event provided by Mable, Mable typically creates both:

• A Custom Event

• A Custom Conversion

For example:

• NewCustomerPurchase

• NewCustomerPurchase (Custom Conversion)

For campaign optimization, you should always optimize for the Custom Event.

Which version you should use for reporting depends on whether your campaigns are already optimizing for NewCustomerPurchase.

Reporting Before Switching to NewCustomerPurchase

If your campaigns are still optimizing for Purchase and you simply want to analyze new customer metrics alongside your existing reporting, use the corresponding Custom Conversions.

Reporting After Switching to NewCustomerPurchase

Once your campaigns are optimizing for NewCustomerPurchase, we recommend using the Custom Events for reporting as well, since they directly reflect the optimization signals sent from Mable to Meta.

Custom Conversions rely on an additional processing layer within Meta. In most cases, the reported values are identical, but minor discrepancies can occasionally occur.

As a general rule:

• Always use the Custom Event for campaign optimization.

• When campaigns optimize for NewCustomerPurchase, use the Custom Event for reporting whenever possible.

• If campaigns are still optimizing for Purchase—or if the Custom Event is not yet available as a reporting column—use the corresponding Custom Conversion instead.

3.1 Why Some Custom Events Are Not Available as Reporting Columns

By default, Meta only makes a Custom Event available as a reporting column after at least one ad set in the ad account has been optimized for that event.

As a result, before you optimize for a specific event for the first time, only the corresponding Custom Conversion is typically available for reporting.

For example, before an ad set has been optimized for NewCustomerPurchase, you'll usually only see NewCustomerPurchase (Custom Conversion) as a reporting column.

The same applies to other Mable events, including:

• ReturningCustomerPurchase

• NetRevenueAllCustomerPurchase

• NetRevenueNewCustomerPurchase

Once an ad set has been optimized for a specific event, the corresponding Custom Event becomes permanently available as a reporting column.

Until then, you can simply use the matching Custom Conversion for reporting.

3.2 What If the Custom Conversion Is Missing?

If the corresponding Custom Conversion is also unavailable, first verify that it has been created in Meta Events Manager.

Navigate to:

Events Manager → Custom Conversions

You should see a Custom Conversion for each Mable event, for example:

• NewCustomerPurchase (Custom Conversion)

• ReturningCustomerPurchase (Custom Conversion)

• AllCustomerPurchase (Custom Conversion)

⚠ Important:
Do not rely on the statistics or status displayed for the Custom Conversion in this overview. The information shown in Meta Events Manager is often unreliable and should not be used to determine whether a Custom Conversion is working correctly.

If the required Custom Conversion does not exist, you can create it manually using the following settings:

• Name: NewCustomerPurchase (Custom Conversion)

• Description: Mable Custom Conversion

• Data Source: Mable Pixel

• Action Source: Website

• Event: The corresponding Mable event (e.g. NewCustomerPurchase)

• Category: Purchase

• Rule: Event Parameter → value → is greater than or equal to → 0

For detailed instructions on verifying and manually creating a Custom Conversion, see ⬇:

Creating a Custom Conversion in Meta Events Manager

4. Setting Up Custom Reporting Columns for New Customer Optimization

To accurately measure new customer performance after switching to NewCustomerPurchase, we recommend adding dedicated new customer reporting columns in Meta Ads Manager.

4.1 Add the Standard Reporting Columns

We recommend adding the following columns:

• NewCustomerPurchase

• NewCustomerPurchase Value

• Cost per NewCustomerPurchase

These metrics show:

• The number of new customers acquired

• Revenue generated by new customers

• Your Customer Acquisition Cost (CAC)

For detailed instructions, see ⬇:

How to Add NewCustomerPurchase Standard Columns in Meta Ads Manager

If the NewCustomerPurchase event columns are not yet available, refer to Section 3.1 for an explanation and the recommended workaround using Custom Conversions.

Step-by-step instructions can be found here ⬇:

How to Create a Custom Column Preset in Meta Ads

4.2 Create Custom Metrics

We also recommend creating two custom metrics:

• NC %

• NC ROAS

These metrics are not available by default in Meta Ads Manager and only need to be created once.

4.3 NC % (New Customer Share)

New Customer Share (NC %) measures the percentage of all purchases that come from new customers. The higher the value, the greater the share of new customers among all purchases.

Formula:

NewCustomerPurchase ÷ Purchase

For detailed instructions, see ⬇:

How to Create an NC% Custom Metric in Meta Ads Manager

4.4 NC ROAS

NC ROAS measures the Return on Ad Spend generated exclusively by new customers.

This allows you to evaluate the profitability of your new customer acquisition efforts independently of your overall ROAS.

Formula:

NewCustomerPurchase Value ÷ Spend

For detailed instructions, see ⬇:

How to Create an NC ROAS Custom Metric in Meta Ads Manager

4.5 Save Your Reporting Preset

Once you've added all relevant new customer metrics, we recommend saving your column configuration as a dedicated reporting preset.

This allows you to quickly access your preferred reporting setup in Meta Ads Manager without having to recreate it each time.

For detailed instructions, see ⬇ :

How to Save a New Customer Reporting Preset in Meta Ads Manager

5. Validate New Customer Optimization with Audience Segmentation

In addition to tracking new customer KPIs, you can use Meta Audience Segmentation to verify whether your campaigns are primarily reaching new audiences.

It's important to understand the role of each reporting method.

For measuring conversions, the Mable Custom Event columns described above provide the most accurate data because they are based directly on the new customer events sent from Mable.

Audience Segmentation is inherently less precise because audience matching is never 100% accurate. However, it is still valuable because it also provides insights into on-platform metrics such as Amount Spent, Reach, and Impressions.

5.1 Configure the Active Customers Audience as Existing Customers

To enable audience-level reporting, you first need to assign the Mable Active Customers Audience as your Existing Customers audience in Meta.

In Meta Ads Manager, navigate to:

Advertising Settings → Audience Segments → Existing Customers

Then select your Active Customers Audience.

5.2 View Audience Segments in Reporting

Once your Active Customers Audience has been configured, you can enable audience segmentation in Ads Manager.

Navigate to:

Breakdown → Demographics → Audience Segments

Meta will then break down campaign performance into audience segments such as:

• Existing Customers

• New Audience

• Engaged Audience (if applicable)

• Unknown (when Meta cannot confidently classify a user)

This allows you to see how your Spend, Reach, and Impressions are distributed across new and existing audiences.

For evaluating actual new customer conversions, we still recommend relying on the Mable Custom Event columns, as they provide more accurate conversion data than Meta's audience segmentation.

For detailed instructions on configuring the Existing Customers audience and using Audience Segments in Meta Ads Manager, see⬇:

How to Set Up Meta Audience Segments with Mable Active Customers

6. Evaluating Performance After the Switch

After switching to NewCustomerPurchase, avoid evaluating campaign performance too early.

Meta needs time to understand the new optimization goal and learn new purchasing patterns.

For many accounts, the learning phase lasts:

• Around one week

• Often 2–4 weeks

• Occasionally longer

During this period, it's normal to see:

• Fluctuating performance

• Higher Customer Acquisition Costs (CAC)

• Lower NC ROAS

• Reduced conversion volume

This is expected.

The more data and budget available, the faster Meta can learn.

To evaluate performance over time, focus on the following KPIs:

• NewCustomerPurchases

• NewCustomerPurchase Value

• Customer Acquisition Cost (CAC)

• NC %

• NC ROAS

These metrics should always be assessed over a sufficiently long time frame rather than based on just a few days of data.

7. Next Step: Meta Tracking & Catalog Setup Best Practices

To ensure accurate attribution and optimal campaign performance, we also recommend following our best practices for Datasets, Catalogs, and Product Matching.

For the complete guide, see ⬇:

Meta Best Practice Setup